More help please. My 1995 P38 4.6 is overheating when left ticking over on a hot day, OK you might say don't let it tick over on a hot day but I am worried about getting stuck in traffic and it overheating, water p*ss*s out of the overflow pipe ontop of the coolant fill level and this accelerates the overheat!!! Ant ideas, is it the thermostat?